In system utilizing electrical components, heat is often generated when electrical power is supplied to the component. With some components, the amount of heat generated can be substantial. In such an environment, the dissipated heat must be continuously removed so as to prevent overheating and damage to the component and/or surrounding electrical circuitry.
One common example of an electrical system in which overheating can be problematic is in systems utilizing high power x-ray tubes for commercial or medical applications. Such tubes are commonly found in various radiographic devices used, for instance in CT (computerized tomographic) scanning for x-ray imaging, x-ray lithography for producing integrated circuits, x-ray diffraction for analyzing materials, and the like. In such devices and applications, a high power, high intensity x-ray tube is arranged to direct radiation through a targeted region. Depending on the particular application, the radiation can be used in various ways. For instance, in a CT scanner, the radiation can be detected after it has passed through the region of interest of a patient's body with one or more detectors, and then analyzed to determine the distribution of absorption of the radiation. In the course of such a procedure, much heat is generated by the x-ray tube as a by-product of the x-ray energy generated. This heat must be continuously removed to prevent damage to the tube (and any other adjacent electrical components) and to increase the x-ray tube's overall service life.
Typically, heat is dissipated in such a device with a coolant liquid or fluid, such as a dielectric oil. In a cooling system of this sort, the x-ray tube is usually disposed within an x-ray tube housing, and a pump is used to continuously circulate the coolant fluid through the housing. Then, as heat is dissipated by the x-ray tube during its operation, at least some of it is absorbed by the coolant fluid. The heated coolant fluid is then passed to some form of heat exchange device, such as a radiative surface in the form of a heat exchanger. Air is passed over the heat exchange (usually with a fan or fans) and, since the air is at a lower temperature than the heated fluid, a portion of the heat is dissipated from the fluid to the outside air. The fluid is then recirculated by the pump back into the x-ray tube housing and the process repeated.
The cooling system of the sort described above is typically implemented with the x-ray tube housing, the pump, and the radiator all interconnected within a closed circulation system, i.e., the fluid circuit for the coolant fluid is not open to the atmosphere. Thus, when heat is generated by the x-ray tube, both the temperature and the volume of the coolant fluid within the closed system increase. As such, the closed system must provide some ability for accommodating volume within in the closed circulation system. Typically, the mechanism that provides this ability is a separate component, often referred to as an accumulator. Usually, an accumulator includes an expandable material, such as a rubber bladder or diaphragm, and a housing or similar structure for protecting the bladder or diaphragm. In known implementations, the accumulator is configured as a separate and discrete component that is interconnected somewhere within the closed circulation system. Consequently, it must include suitable fluid fittings and conduits so that it can be physically connected within the closed system. In operation, as the coolant fluid is heated, and the fluid volume within the closed system increases, the expandable bladder/diaphragm correspondingly expands and thereby maintains the integrity of the closed system. Conversely, a decrease in temperature and volume is also accommodated by a corresponding contraction of the flexible diaphragm.
As noted, in the prior art the accumulator is designed as a component separate and distinct from the rest of the components within the closed system. Such an approach has resulted in several undesirable characteristics, primarily due to the need for additional fluid connection points to physically connect the accumulator within the closed system. This gives rise to a need for additional parts and for additional assembly time and complexity, resulting in a system that is difficult to install, replace and repair. Moreover, additional fluid fitting interconnection points raise the probability that the system will leak coolant fluid during operation.
As such, there is a need for a system in which the accumulator is not implemented as a separate and discrete component within the closed system. This would eliminate the need to have additional fluid connection points within the closed system, and reduces the number of parts present. A reduction in parts reduces the overall complexity of the system, as well as the time needed for its initial assembly and subsequent servicing. In addition, reduction in fluid connection points reduces the chance for part failure and fluid leakage, and would provide a more reliable system.